1. Field of the Invention
This invention relates generally to printing devices, such as laser printers or ink-based printers, and, especially, to color printers. More particularly, this invention relates to apparatus and method for improved printing tests, for example, testing for toner/ink availability, defects such as streaks or fading, and, preferably, alignment of colors relative to each other. The invention relates to systems for saving the paper on which test patterns are conventionally printed. Also, the invention may be adapted to save other consumables, notably, by reducing the amount of toner or ink used for test patterns.
2. Related Art
Conventionally, test patterns are printed by printers, as requested or as preprogrammed, to indicate toner availability and printing quality. A test page usually comprises a pattern, logo, and/or data over most of a page, which shows: whether all colors of toners are available and operable, whether all colors are printing without detects, and whether the four primary colors are aligning properly to form proper patterns and color-tones that are necessary for high quality color printing. Many computer and printer systems include options for setting the frequency of test page printing, for example, once before every print job, or only upon request. Typically, a test page is also automatically printed each time a printer is restarted after being turned off or after a power failure. Each time a test page is printed, a sheet of paper is used, and the toner required to cover a substantial portion of the sheet is used, after which the test page is visually checked and discarded.
There is a need for reducing the waste inherent in the test page process, while maintaining the user or the repairperson""s access to the information conveyed by the test page process. There is a need for an improved test process that reduces, at a minimum, paper usage, while still indicating whether printing of all four toner colors is within acceptable quality limits. The present invention addresses these and other needs.
The present invention comprises apparatus and methods providing intuitive visual feedback regarding printing performance, by allowing a user or other person to look into the printer at a test pattern. The feedback does not require paper or other media to be ejected out from the printer and then thrown away. The feedback on printer performance is contained preferably entirely within the printer, and comprises only toner/ink usage. The invented test printing system gives feedback on printer performance preferably at least in some or all of the following areas: toner/ink availability, and whether the developer(s) or cartridge(s) are printing without significant defects and with the colors properly aligned.
Preferably, the invented test printing system provides this visual feedback preferably without requiring opening of the printer or removing any parts from the printer. The invented system provides a preferably non-disposable, nonconsumable test print surface that is positioned, or movable to be, in a user""s view through an opening in the housing. Preferably, in cases where the test print surface is movable, it moves automatically during the test operation, after the test pattern is printed, to be in view of the window or doorway. The opening is preferably a transparent window, which allows viewing of the test pattern without exposing the test print surface to the outside environment, or, less preferably, the opening may be a doorway covered by a movable door.
In a preferred embodiment for a color laser printer, a test xe2x80x9cpatchxe2x80x9d is printed on the intermediate transfer belt and positioned behind/below a window through the printer housing so that the user/repairperson may look through the window at the test patch. The test patch preferably is not transferred to paper, but only resides on the transfer belt for a specified duration until the toner is wiped off the transfer belt and disposed of in the waste toner receptacle inside the printer.
In an ink-based printer, such as an HP Inkjet(copyright) printer, there is typically no transfer belt or other intermediate image-carrying member, because ink is applied directly onto paper during either normal printing or test page printing. Therefore, an ink-style embodiment of the present invention provides a test surface, inside the printer, on which the cartridge prints the test patch. The test surface is positioned in, or moves into, view through a window provided through the printer housing, for viewing of the test patch by the user. Alternatively, the test surface is easily seen by the user upon opening a door in the housing to reveal the test surface. As in the preferred laser printer embodiments, the test patch resides on the test surface for a specified duration until the toner is wiped off the test surface and disposed of in a waste toner receptacle inside the printer.
In ink-based printers, the ink cartridge may be adapted to move to the test surface for printing of the test pattern, and then to move away from the test surface to reveal it to someone looking through a window or doorway. Alternatively, the test surface of an ink-based printer may be adapted to move between various locations, that is, typically from an ink-receiving position adjacent the ink cartridge, to a display position, and then to a cleaning position.
The test patch is designed to be a size and pattern sufficient to show the user, at a minimum, whether all colors are printing. Additionally, the size and pattern are preferably sufficient to show whether there are defects, such as streaking or fading, in any of the color areas, and whether the colors are properly aligned so that the pictures of many color tones will result from the four primary toner colors. Preferably, the test patch is approximately as wide as the developers, photoconductor, and transfer belt, to show print quality across a full-page-width.